Automatically ensure Deno language services are enabled when a notebook uses a Deno kernel

[kitsonk]

Is your feature request related to a problem? Please describe.

Currently when you have a project and are working on a Jupyter Notebook and have Deno as the selected kernel, but haven't explicitly enabled Deno or created a deno.json in the workspace, the Deno language service does not activate.

Especially since you can specify imports directly in the notebook and not having a deno.json makes the notebook far more portable, automatically activating the language server when the notebook's kernel is Deno would make sense.

Ref #1102

Describe the solution you'd like

Automatically activate the language services when a workspace contains an open Jupyter Notebook with Deno as the selected kernel.